65% of developers starting #Kotlin project choose RxJava 2 as a background work tool. But are you sure the choice is justified? Kotlin coroutines can be a powerful replacement for RxJava in an Android project. In this talk, we are going to compare the approaches, consider their pros and cons, and see when coroutines are more convenient, and when you are doomed without Rx. We will also see how unit testing differs between two approaches and how they can live together in a project.